Vacuum frame for printing upon sensitized surfaces



H. C. JONES VACUUM FRAME FOR PRINTING UPON SENSITIZED SURFACES Filed March 25. 1922 Patented Dec. 25, 1923.'

UNITED STATES PATENT OFFICE.

HARRY C. JONES, OF LARCHMONT, NEW YORK, ASSIGNOR TO LITHOPRINTEX CORPOBA-i TION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VACUUM FRAME FOR PRINTING"UPONJSENSITIZED SURFACES.

Application led March 25, 1922. Serial No. 546,579.

T 0 all whom it may concern j Be it known that I, HARRY C. JoNns, a citizen of the United States, and resident of Larchmont, in the ,county of Westchester and State of New York, have invented certain new fand useful Improvements in Vacuum Frames for Printing upon Snsitized Surfaces, of which the following is a specilication.

My invention relates to vacuum frames for printing upon sensitized surfaces, and the invention is especially useful for contact printing from a negative or other transparency onto a sensitized surface of larger area than said negative, and which for one reason or another is not conveniently placeable, or capable o-f being p-laced in a printing ame.

The invention contemplates a frame forI receiving and supporting the negative and means for sealing the frame and negative upon a portion only of the sensitized surface, then creating a vacuum in the space between the `parts to produce firm contact, and then exposing the negative to a light source.

The principal object of my invention is to provide a vacuum frame especially useful for contact printing between` a negative and a portion only of a sensitized surface, and by the use of which when used for printing only on a portion of the sensitized surface the negative may be handled more conveniently andv rapidly and the printing accomplished more accurately lthan has been the vcaso heretofore with contact printing. In

carrying out my invention I provide a frame to hold the negative and support it in proper position on the frame from relative laterali. e., parallel, movement with respect to the frame, and I provide means by which the negative may be sealed over a ortion only of the sensitized surface, with suitable means whereby the air may be exhausted, from over the portion of the sensitizedv surface covered by the 'negative so as to cause the surface and negative to be forced together to hold the two inI lirm contact. The invention thus not only enables the 'elimination ofthe usual blanket or glass pressure plate covering or enveloping the entire sensitized surface, but it enables a quick and accurate handling of the negative yin contact printing, as will hereinafter be explained. According to my invention, I am enabled to seal off any selected part or portion of the ,whole sensitized surface corresponding to the size `of the negative used, and exhaust air from the space between such portion only of the sensitized surface and the negative, so as to produce the desired firm contact, and this can be done while the sensitized surface is held in any position or supported in some special machine. The invention is applicable to printing on any suitable sensitized surface. i

for holding the negative within the frame,

view on line C-D ig. 4 is a sectional of Fig. 3; and

Fig. 5 is a sectional view of the negative on line E-F of Fig. 4,'showing the milled slot for clamping thenegative in the frame.

The printing frame may consist of a rectangular or otherwise formed body member l provided with an opening 2, of any convenient form, for the passage of light through the negative. On one side of the frame 1, i. e., the side adapted to lie adjacent the sensitized surface and which I Jwill call the front side, is formed a recess to receive the negative; the outer.` edges 5, 5 of which ,may 'reston the finished surface 6,6 of recess 3, while suitable projections or lugs 7, 7 formed on two of the vertical sides of said recess 3 provide means for positioning and with the aid of adjustable clamps 8, 8, for holding the negative rigidly within the recess of the frame.

FTo hold the negative within the frame and to' prevent the holding lugs 7, 7 and clamps 8, 8 from projecting above the contacting surface of the negative, any suitable means may be adopted such as beveling the .edge of the negative andthe holding lugs or clamps, as is clearly shown in Fig. 2, or by any other means such as illustrated in Figs. f 3, 4 and 5, where a beveled slot or vrecess 9 cut in the edge of the negative, is adapted to be engaged by an adjustable clam 8.

The invention consists in the novel fea Clamps 8, 8 muy vbe formed with asing e or` @ne l ,the frame and positioned or Vlocated by the double bevel, to conform to the character of holding down means provided on the negative, and are eccentrically and pivotally mounted on shouldered screws 11, 11. By

l means of their beveled edges and eccentricity, the clamps 8, 8 tend to force the negative against the locating lugs 7, 7 for position, and to press it down firmly against the edges 5, ofrecess 3. Tension springs 12, 12 attached to clamps 8, 81,- by pins 13, 13, and to frame 1, by pins 1t, 11i, tend at all times when on one side of their pivotal cenchannel 16 cutin frame 1. rlFhe sealing member maybe of leather, rubber, or any suitably yielding or dexible material, and is preferably formed in one continuous piece with an inner projecting Harige 17, the upper side or surface of which is 'in 'contact with the negative while the under side is free to bril acted upon by the pressure of the atmosp ere.

Means for sealing the frame with the sensitized surface on which a rint is to be made is provided in a similar e'xible member 18 rigidly held in the channel or groove 19 of frame member 1. rlfhe member 18 projects above the frame member l. andis provided withfa'at surface and a continuous exten'- sion flange or lip 20.

When assembled in frame 1, the. upper or contacting surface of the negative d is but little below the surface Iof the yielding flange or seal of member 18 so that' when said dange is brought in contact with any dat surface 22 a closedchamber is formed between that surface, the frame' member and the negative. Preferably the sealing member 18 should be so constructed as not to cause any lateral shifting of the negative and frame with respect to the sensitizedsurface when the vacuum between the negative and the sensitized surface is produced.

Suitable means are provided for eirhaust- 'ing the air from said space. This may confsist of a nipple y24 screwed'into a bore in the frame, and provided with a suitable springpressed ball check valve, andmeans for connectirng the nipple with an exhaust pump or exhaust r ceiver.

rlhe operation of the apparatus is as follows.: In practice the negative is lplaced in lugs 7, 7 and held in place bvclamps 8, 8.y

Thel frame is thei moved into position o po-Y site the sensitized surface andthe sea `i .member 1 8 is placed. in eontact'with the portion of the sensitized plate or surface on which a print is to be made, and the air is exhausted from the closed chamber. The pressure of the atmosphere forces the negative and sensitized `plate together iii. intimate contact and holds them in such contact until the vacuum in the closed chamber is broken.

Light to the sensitized surface is admitted through the negative by the opening 2 of frame 1.

flitiitable lugs 25, 25 are provided on frame member 1 by which said frame may be supported by bolts or any other means and held in proper position with respect `to the sensitized surface during exposure.

lt will be understood that the vacuum is `not necessarily ,relied upon to support and position the frame with respect to the sensitir/Jed surface, but merely to insure the desired contact. and supported by other suitable means.

The frame is positioned 1t might be pointed out that the general L form of sealing means shown, i. e., the rubben ribs or flanges 15v and 18 with the relatively stout body portion `and the relatively thin flexible lips 20, is of special advantage because while the body is rm enough, the

lip provides a reliable quick acting seal even on distorted surfaces.

'llhe invention while generally useful, has

special application in what are known as step and repeat machines. Such machines are well known in the art, and one such machine is described, for example, in United States Letters Patent No. 1,131,631,

ioo

granted March 9, 1915, for an invention of Herbert M. Pilkington. It is desirable in some cases to use a machine of this character for stepping and repeating designs from a ,negative directly onto a sensitized metal surface such 'as a sensitized zinc plate, utilizing in such'steppin and repeating the principle of. contact printingpinstead of the principle of projecting. by means of lenses. 3

This invention makes it possible in such maj chines to utilize such contact printing; holding the negative and sensitized surface' into contact by pneumatic pressure rather than by having to force the lsurfaces into close con- LtactA by` mechanical ymeans rwhich vmight strain the precision partso such a machineb ln using'the inventionhina step and repeat machine which 1n some forms is known as ia yphoto-composing machine, the negative frame with the negative will be supported securely upon the horizontally and vertically sliiftablecarriage, and the sensitized zinc -being shifted tdward and from the carriage to ,move the zinc platetoward, and fpgxnthe carriage, 'I

Whiie I have described my invention with particuiarity in connection with the preferred form herein shown and described, it Will be understood by those skilled in the art, after understanding the same, that various changes in the form, arrangement and construction of the parts may be made Without departing from the spirit 'or scope of the invention, and i aim in the appended claims to cover aii suchY changes and modifications as are Within the scope of the invention. Novel subject matter herein described and not ciaimed is covered by other pending appiications.

Having thus described i ciaim as nevv and ters Patent, is:

i. iin apparatus of the character described, the combination of a frame for receiving and holding a negative to printed from onto a sensitized surface9 means for positioning and securing the negative a tired position upon 'the frame at the front side thereof from iaterai movement reiative thereto so that the frame and negative secured thereto may be moved together with respect to the sensitized surface9 means operativeij/ reiated said sensitized surface frame and negative and serving to seai ont from the atmosphere that portion of the sensitized surface covered by the negative7 and means of communication for exhausting 'the air from over said portion of the sensitized surface to cause the negative to be forced intorengagement the samea 2. in apparatus ti e characterr scribed9 combination of a frame for receiving and holding a negative to be printed from onto a sensitized surface9 said frame having means for securingthe negative thereto from reiative iaterai movement so that the frame'ivith the negative secured in predetermined position may be moved together `with respect to the sensitized surface, said frame aise having means for sealing the negative thereto when the air is exhausted from bett-veen the negative and sensitized surface9 means for sealing the frame .to the sensitized surface7 and means of communication for exhausting the air from over the portion of sensitized surface covered by the negative to cause the negative to be forced into engagement with said surface.

3.. iin apparatus of the character described, the combination of a frame for a negative, having a yieidabie member around the same for engaging and seating the marginai edges of the negative to frame, and having another yieidabie member, around the frame adapted normaiiy to project above the adjacent surface of the negative for engaging and sealing the frame to a co-operating sensitized surface, and means for admitting air to and exhausting it from the space between said negative, surface and frame my invention, what desire to secure by Let- 4. In apparatus of the character described, the combination of a frame for a negative, a sealing member around the inner portion of the frame7 having a continuous lip adapted to engage one side of the negative when in the frame, said lip having its opposite side exposed to the atmosphere, a second sealing member around the outer portion of the frame and above the first sealing member, and also having a continuous lip adapted to engage a sensitized surface on one side andhaving its opposite side exposed to the atmosphere, and means of communication for exhausting the air from between the sensitized surface and negative.

5. in apparatus of the character described, the combination of a frame for a negative, means for positioning and hoiding the negative in a tired position upon the frame means around the frame for seaiing the marginai portions of the negative with respect to the frame7 means around the frame for seaiing the frame with respect to a co-operL ating sensitized surface and means of communication for exhausting the air from said seaied off space between the sensitized surface and negative 6. in apparatus of the character described, the combination of a frame for receiving and holding a negative to be printed from onto a sensitized surface, said frame supportino the negative and .securing it from iaterai movement relative thereto so that the frame and negative secured thereto may bexmoved together with respect tothe sensitized surface said frame having means serving to seai the negative Within the frane, Said frame also having a yieidable member extending around same and adapted to engage the sensitized surface to form a seaiing joint therewitha and means of communication for exhausting the air from over the portion ofthe sensitized surface covered by the negative to cause the two to be forced together.

7. iin apparatus of the character dem scribed, the combination of a frame for a negative, means for positioning and holding the negative in a position upon the frame, means around the frame for seaiing it with one side of the negative, means around the frame on the opposite side of the negative for seai'ing the frame to a cooper ating sensitized surface, and means for admitting air to and exhausting it from the space between said negative7 surface and frame. 5

. 8. in apparatus of the character described, the combination of a frame for a i-iegative7 means on tivo adjacent sides of the frame against which the negative is to abut7 means on the other tivo sides of the frame for holding the negative 4against said irst two sides, means around the inner portion of the frame for seating it with one side of eci ifiomoiito o, semsitieii surface, said treme supporting? the negative emi seeming it from ieteiviii movement relative thereto eo tiiet the/immo omi megotive secured thereto @weee-e may 'be moved togetiiein with respect to the v sensitized suifece, means :tor sealing the fre omi megotive over o portion ot the eemsitizedi suitece, emi means of communi cetion 'for exheu in the oifi romover the poi-tion of the sensitized surface covered toy the negative to ceuse the two to be forced together.

iin testimony Wheieoit ii hote sieoi` my 2@ meme to this specicotioii.

HARRY C. JU/NES.,- 

